Tinguiririca is a complex stratovolcano west of the Chile-Argentina border in central Chile. The volcano consists of overlapping small stratovolcanoes, cinder cones and craters that have developed over an NNE-SSE trending fissure. The youngest appear to be Tinguiririca and Fray Carlos. A single historical, probably phreatic eruption from Tinguiririca was recorded in 1917. There was an un-confirmed report of an eruption in 1994.

The Tinguiririca complex was constructed during 3 eruptive cycles dating back to the middle Pleistocene.

Constant fumarolic activity occurs within and on the NW wall of the summit crater of Tinguiririca, and hot springs and fumaroles with sulfur deposits are found on the western flanks of the summit cones.